While it is amusing to take at face value, the actor‘s face isn’t really doing this, of course. The unintentional morphing alien effect is the result of compression errors with the data stream. This is one of the most interesting distortions I’ve seen, and it is happening to an actor who plays the part of a supernatural being (vampire) in the movie he is discussing.
The compression software used in this video reduces the amount if data transmitted by guessing what, in the next frame, a certain pixel will be based on what it was in the previous frame. This introduces successive errors and the image degrades from the original, until a key frame is transmitted and the real image is again restored.
When motion prediction is used, as in MPEG-1, MPEG-2 or MPEG-4, compression artifacts tend to remain on several generations of decompressed frames, and move with the optic flow of the image, leading to a peculiar effect, part way between a painting effect and “grime” that moves with objects in the scene.
Data errors in the compressed bit-stream can lead to errors similar to large quantization errors, or can disrupt the parsing of the data stream entirely for a short time, leading to “break-up” of the picture. Where gross errors have occurred in the bit-stream, decoders continue to apply updates to the damaged picture for a short interval, creating a “ghost image” effect, until receiving the next independently compressed frame. In MPEG picture coding, these are known as “I-frames”, with the ‘I’ standing for “intra”.